Gold-skarn deposits in Northeast Russia     

A. V. Volkov  V. A. Sidorov  A. A. Sidorov 《Doklady Earth Sciences》2008,419(1):210-213

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Native gold of the porphyry copper mineralization in the Borov Dol deposit (Republic of Macedonia)     

A. V. Volkov  V. Stefanova  T. Serafimovski  A. A. Sidorov 《Doklady Earth Sciences》2008,422(1):1013-1017

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Flow over mountains with the stream velocity shear     

V. N. Kozhevnikov  K. B. Moiseenko  B. I. Volkov 《Izvestiya Atmospheric and Oceanic Physics》2016,52(6):587-595

The dependence of orographic disturbances of the atmosphere on properties of the incident flow is studied within the semianalytic approach. Reducing the initial system of equations of hydrothermodynamics to a single equation for an associative stream function makes it possible to consider a class of solutions of a sufficiently general type when the background velocity of the wind and the Lyra’s scale vary with height. It is shown that the dependence of the solution on the indicated factors can be not only strong, but also sufficiently unexpected. In particular, with the monotonic growth in the wind velocity in the troposphere, which corresponds to conditions of a jet stream near the tropopause, disturbances at low and medium heights can acquire an almost resonant and waveguide nature.  相似文献   

Cu–Ag sulfides as indicators of pre-porphyritic epithermal Au–Ag deposits in Northeastern Russia     

N. E. Savva  A. A. Sidorov  A. V. Volkov 《Doklady Earth Sciences》2016,469(2):782-786

Au–Ag mineralization of the Olcha and Teploe epithermal deposits underwent thermal metamorphism due to porphyritic intrusions. The presence of Bi-bearing galena and matildite in the ores (Teploe), Cu–Te-bearing naumannite (Olcha), the occurrence of middle- and high-temperature facies of metasomatic rocks (epidote and actinolite), and temperature formation conditions are related, firstly, to the influence of granitoids on the ore process, which supplied not only Cu and Mo, but also Bi, Te, and, secondly, to the heating of host rocks containing pre-porphyritic epithermal Au–Ag mineralization. The abundance of Cu–Ag sulfides and Cu-acanthite resulted from the enrichment of later mineral phases in Cu and Ag under the substance redistribution with the formation of Ag-acanthite ores. The data considered in the paper are of practical importance for regional forecasting of metallogenic constructions, exploration, and evaluation of the epithermal Au–Ag deposits.  相似文献   

On the role of contamination and hybridism in formation of the composite Raumid pluton granites (Pamir Mnts.): Results of Sm–Nd Isotope Study     

V. N. Volkov  K. N. Shatagin  A. Yu. Kramchaninov 《Doklady Earth Sciences》2016,470(1):981-984

This work presents isotope Sm-Nd data obtained for bulk samples of granites of all 8 emplacement phases of the Raumid granite massif, which occurred 35 Ma ago at a hypabyssal depth during the orogenic stage of development of Southern Pamir fold system. The ¹⁴⁷Sm/¹⁴⁴Nd ratio in studied collection of granite samples ranges between 0.091 and 0.323; the ε_Nd(T) value is–4.0. The Sm-Nd isotope study results suggest that all granite varieties distinguished in the Raumid massif are comagmatic formations and contamination and hybridization processes did not play any role in REE distribution in granites. At this, the source of parental magma did not change during granite generation. We assume that the only process, resulted in the trace element evolution in granites, was differentiation of three batches of magma sequentially uplifted from the source.  相似文献   

Parametrical modelling of the spectra of small-scale electrical conductivity pulsations in the ocean     

V. I. Butyrev  I. I. Volkov  I. D. Lozovatsky 《Physical Oceanography》1990,1(3):203-209

Parametrical models of the spectra of small-scale electrical conductivity and current velocity pulsations in the ocean are considered.Translated by V. Puchkin  相似文献   

On the problem of the computation of spectra of small-scale inhomogeneities in hydrophysical fields of the ocean     

I. I. Volkov  N. D. Gordeev  I. D. Lozovatsky 《Physical Oceanography》1990,1(4):295-301

A novel form of correlation window employed to calculate the spectral density of a random process using a Fourier transform of the correlation function is proposed. It is shown that, concerning its metrologic characteristics, the value of the spectral density obtained does not yield the best autoregression estimates. A fast recurrent estimational algorithm is suggested to increase the efficiency of the calculational procedure.Translated by M. M. Trufanov.  相似文献   

Light Curves of the Type II-P Supernova SN 2017eaw: The First 200 Days     

D.?Yu.?TsvetkovEmail author  S.?Yu.?Shugarov  I.?M.?Volkov  N.?N.?Pavlyuk  O.?V.?Vozyakova  N.?I.?Shatsky  A.?A.?Nikiforova  I.?S.?Troitsky  Yu.?V.?Troitskaya  P.?V.?Baklanov 《Astronomy Letters》2018,44(5):315-323

We present the results of our UBVRI photometry for the type II-P supernova SN 2017eaw in NGC6946 obtained fromMay 14 to December 7, 2017, at several telescopes, including the 2.5-m telescope at the CaucasusHigh-Altitude Observatory of the SAIMSU. The dates andmagnitudes atmaximumlight and the light-curve parameters have been determined. The color evolution, extinction, and peak luminosity of SN 2017eaw are discussed. The results of our preliminary radiation–gasdynamic simulations of its light curves with the STELLA code describe satisfactorily the UBVRI observational data.  相似文献   

Cytochrome P4501A expression,chemical contaminants and histopathology in roach,goby and sturgeon and chemical contaminants in sediments from the Caspian Sea,Lake Balkhash and the Ily River Delta,Kazakhstan   总被引：1，自引：0，他引：1  

Moore MJ  Mitrofanov IV  Valentini SS  Volkov VV  Kurbskiy AV  Zhimbey EN  Eglinton LB  Stegeman JJ 《Marine pollution bulletin》2003,46(1):107-119

Roach, goby and sturgeon were examined for cytochrome P4501A (CYP1A) expression and histopathology, in relation to contaminant burdens in fish and sediment. Gradients of induction of CYP1A were observed. Roach from the Ural and Ily River Deltas and roach and goby from the two stations nearest the Caspian Sea oil fields displayed higher levels of CYP1A expression in several organs than was observed in fish from further offshore. Great sturgeon and Russian sturgeon showed higher levels of CYP1A expression than was seen in starred sturgeon and gobies in the Ural delta. No fish showed evidence of contaminant-related histopathologies in the organs examined, despite the elevated CYP1A levels. Low levels of polychlorinated biphenyls and elevated levels of inshore and riverine petroleum hydrocarbons from these habitats suggest that this ongoing hydrocarbon exposure, and that from natural sources and long-term oil exploration on the Northeastern Caspian shore, contributed to the CYP1A induction observed.  相似文献   

Venus: Preliminary prediction of the mineral composition of surface rocks     

I.L. Khodakovsky  V.P. Volkov  Yu.I. Sidorov  M.V. Borisov  M.V. Lomonosov 《Icarus》1979,39(3):352-363

A thermodynamical analysis of the multicomponent system SiTiAlFeMnMgCaNaKPCHO open with respect to CO₂, CO, H₂O was carried out. Hydration and carbonatization processes are proposed to be geochemical consequences of the hypothesis of quasi-equilibrium conditions between the troposphere and crustal surface rocks. The probable rock-forming hydrated mineral phases are represented by epidote, glaucophane, tremolite, phlogopite, and annite; the carbonatization results in existence of calcite and dolomite as rock-forming minerals of weathered alkaline lavas. The surface rocks are assumed to have high ferric/ferrous iron ratios. The wollastonite equilibrium is rejected as a buffering chemical reaction. Hydrated minerals could be stable at least up to 5-km depths and contribute about 0.1 × 10²⁴ g of H₂O whereas about (0.7–0.8) × 10²⁴ g of H₂O would be consumed in ferrous iron oxidation with concomitant hydrogen dissipation. The distribution of H₂O in the outer planetary shells is possibly a function of their temperatures.  相似文献